I do not believe they make those anymore. I believe they are called Taylor garage doors. The way I've gotten them in the past is by picking them up out of the back of garage door places. They typically have a large pile of them sitting in the back. Some places if you call will tell you what they have.
Is it the pivot arm that has failed? If so all you need are new arms. Much easier to find intact. Just measure everything off to make sure you're taking the right ones.